Device trigger dampening mechanism

ABSTRACT

In various embodiments, a surgical instrument comprising a handle assembly, a shaft assembly, and an end effector are disclosed. In one embodiment, the handle assembly comprises a closure trigger and a yoke coupled to the closure trigger. Actuation of the closure trigger drives the yoke longitudinally in a first direction. A closure spring is coupled to the yoke. Longitudinal movement of the yoke in the first direction compresses the closure spring. A directional return stroke damper is coupled to the yoke. The directional return stroke damper is configured to provide a dampening force to longitudinal movement of the yoke in a second direction. A shaft assembly comprising a proximal end and a distal end is coupled to the handle. An end effector comprising a first jaw member and a second jaw member is coupled to the distal end of the shaft assembly.

BACKGROUND

The present disclosure is related generally to electrosurgical deviceswith various mechanisms for clamping and treating tissue. In particular,the present disclosure is related to electrosurgical devices withvarious mechanisms for dampening a device trigger return stroke.

While several devices have been made and used, it is believed that noone prior to the inventors has made or used the device described in theappended claims.

SUMMARY

In various embodiments, a surgical instrument is disclosed. In oneembodiment, the surgical instrument comprises a handle assembly. Thehandle assembly comprises a closure trigger and a yoke coupled to theclosure trigger. Actuation of the closure trigger drives the yokelongitudinally in a first direction. A closure spring is coupled to theyoke. Longitudinal movement of the yoke in the first directioncompresses the closure spring. A directional return stroke damper iscoupled to the yoke. The directional return stroke damper is configuredto provide a dampening force to longitudinal movement of the yoke in asecond direction. A shaft assembly comprising a proximal end and adistal end is coupled to the handle. An end effector is coupled to thedistal end of the shaft assembly. The end effector comprises a jawassembly having a proximal end and a distal end. The jaw assemblycomprises a first jaw member and a second jaw member. The closure springis operatively coupled to the first jaw member to pivotally move thefirst jaw member from an open position to a closed position relative tothe second jaw member when the closure spring is compressed by the yoke.

In various embodiments, a jaw closure mechanism for a surgicalinstrument having an end effector comprising a first jaw member and asecond jaw member is disclosed. In one embodiment, the jaw closuremechanism comprises a yoke longitudinally moveable in a first directionand a second direction. The first and second directions are opposite. Aclosure spring is coupled to the yoke. Longitudinal movement of the yokein the first direction compresses the closure spring. A directionalreturn stroke damper is coupled to the yoke. The directional returnstroke damper is configured to provide a dampening force to longitudinalmovement of the yoke in the second direction.

In various embodiments, a surgical instrument is disclosed. The surgicalinstrument comprises a handle assembly. The handle assembly comprises aclosure trigger defining an energy button hole. A yoke is coupled to theclosure trigger. Actuation of the closure trigger drives the yokelongitudinally in a first direction. A closure spring is coupled to theyoke. Longitudinal movement of the yoke in the first directioncompresses the closure spring. A directional return stroke damper iscoupled to the yoke. The directional return stroke damper is configuredto provide a dampening force to longitudinal movement of the yoke in asecond direction. An energy button is located within the energy buttonhole. The handle assembly further comprises a firing trigger. A shaftassembly is coupled to the handle assembly. The shaft assembly comprisesan outer tube, a closure actuator operatively coupled to the closurespring, and a firing actuator operatively coupled to the firing trigger.An end effector is coupled to a distal end of the shaft assembly. Theend effector comprises a jaw assembly having a proximal end and a distalend. The jaw assembly comprises a first jaw member and a second jawmember. The first and second jaw members define a longitudinal slot. Theclosure actuator is coupled to the first jaw member to pivotally movethe first jaw member from an open position to a closed position relativeto the second jaw member. A cutting member is deployable within thelongitudinal slot. The cutting member is coupled to the firing actuatorto advance the cutting member distally within the longitudinal slot.

DRAWINGS

The novel features of the embodiments described herein are set forthwith particularity in the appended claims. The embodiments, however,both as to organization and methods of operation may be betterunderstood by reference to the following description, taken inconjunction with the accompanying drawings as follows.

FIG. 1 illustrates one embodiment of an electrosurgical instrument.

FIG. 2 illustrates a side-perspective of the electrosurgical instrumentof FIG. 1.

FIG. 3 illustrates a side-view of the electrosurgical instrument of FIG.1.

FIG. 4 illustrates a perspective view of the electrosurgical instrumentof FIG. 1 with a left handle housing removed.

FIG. 5 illustrates an exploded view of the electrosurgical instrument ofFIG. 1.

FIG. 6 illustrates a side view of the electrosurgical instrument FIG. 1comprising a jaw closure system in the handle assembly.

FIG. 7 illustrates the electrosurgical instrument of FIG. 6 with the jawclosure system in a partially-closed position.

FIG. 8 illustrates a firing mechanism lock-bar interfaced with cuttingmember firing mechanism.

FIG. 9 illustrates a closure trigger rotated sufficiently to disengage alock bar from a rack unlock block.

FIG. 10 illustrates the firing mechanism lock-bar of FIG. 8 in anunlocked position.

FIG. 11 illustrates one embodiment of a jaw position sensor.

FIG. 12 illustrates one embodiment of a jaw position sensor comprisingan adjustment screw lock spring.

FIG. 13 illustrates one embodiment of a jaw position sensor.

FIG. 14 illustrates one embodiment of a jaw position sensor mounted in ahandle assembly.

FIG. 15 illustrates one embodiment of the electrosurgical instrument ofFIG. 4 with the closure trigger fully actuated.

FIG. 16 illustrates the electrosurgical instrument of FIG. 4 with aclosure trigger lock engaged.

FIG. 17 illustrates the electrosurgical instrument of FIG. 16 with afiring trigger in an actuated position.

FIG. 18 illustrates one embodiment of a yoke of a jaw closure systemcoupled to a directional return stroke damper.

FIG. 19 illustrates one embodiment of return stroke damper.

FIG. 20A illustrates the interface between a yoke and a directionalreturn stroke damper when the jaws of an end effector are in a closedposition.

FIGS. 20B-20C illustrates the interface between the yoke and thedirectional return stroke damper when the jaws of the end effectortransition to an open position.

FIG. 20D illustrates the interface between the yoke and the directionalreturn stroke damper when the jaws of the end effector are in a fullyopen position.

FIG. 21 illustrates the electrosurgical instrument of FIG. 4 with theclosure trigger lock released and the closure trigger in a releasedposition.

FIG. 22 illustrates one embodiment of a rack spring washer.

FIG. 23 illustrates one embodiment of a jaw closure spring stop.

FIG. 24 illustrates one embodiment of an electrical energy systemcomprising an energy button, a source cable, and a return cable.

FIG. 25 illustrates one embodiment of an electrosurgical instrumentcomprising a pre-compressed jaw closure spring.

FIG. 26 illustrates one embodiment of an electrosurgical instrumentcomprising a top-mounted knife firing gear and rack.

FIGS. 27A and 27B illustrate one embodiment of an electrosurgical endeffector comprising a curved shape.

FIG. 28 illustrates one embodiment of the electrosurgical end effectorof FIGS. 27A-27B comprising an off-set jaw closure actuator.

FIG. 29 illustrates one embodiment of an electrosurgical end effectorcomprising a first jaw member and a second jaw member having a smoothtaper, curved shape.

FIG. 30 illustrates one embodiment of the electrosurgical end effectorof FIG. 29 in a closed position.

FIG. 31 illustrates one embodiment of a lower jaw of the electrosurgicalend effector of FIGS. 29-30 comprising a curved longitudinal cuttingmember slot.

FIG. 32 shows a graph illustrating the mechanical advantage of theclosure trigger at various trigger angles.

FIG. 33 shows a graph illustrating force delivered by the jaws when notissue is located within the jaws.

FIG. 34 shows a graph illustrating force delivered by the jaws when atissue section is located within the jaws.

FIG. 35A illustrates one embodiment of a directional fluid dampercoupled to a yoke when the jaws of an end effector are in a closedposition.

FIG. 35B illustrates the directional fluid damper of FIG. 35A as thejaws of the end effector transition from a closed position to an openposition.

FIG. 36 illustrates one embodiment of a surgical instrument comprising adirectional fluid damper configured to provide return stroke dampeningfor the closure trigger.

FIG. 37 illustrates one embodiment of a directional air damper.

FIG. 38 illustrates one embodiment of an opening of the directional airdamper of FIG. 37.

FIG. 39 illustrates one embodiment of a surgical instrument comprising acompressible yoke pin configured to provide return stroke dampening forthe closure trigger.

FIG. 40A illustrates one embodiment of a compressible yoke pin in anuncompressed position.

FIG. 40B illustrates the compressible yoke pin of FIG. 40A in acompressed position.

FIG. 41 shows a graph illustrating the damper effect on a return loadprovided by a directional return stroke damper.

DESCRIPTION

In the following detailed description, reference is made to theaccompanying drawings, which form a part hereof. In the drawings,similar symbols and reference characters typically identify similarcomponents throughout the several views, unless context dictatesotherwise. The illustrative embodiments described in the detaileddescription, drawings, and claims are not meant to be limiting. Otherembodiments may be utilized, and other changes may be made, withoutdeparting from the scope of the subject matter presented here.

The following description of certain examples of the technology shouldnot be used to limit its scope. Other examples, features, aspects,embodiments, and advantages of the technology will become apparent tothose skilled in the art from the following description, which is by wayof illustration, one of the best modes contemplated for carrying out thetechnology. As will be realized, the technology described herein iscapable of other different and obvious aspects, all without departingfrom the technology. Accordingly, the drawings and descriptions shouldbe regarded as illustrative in nature and not restrictive.

It is further understood that any one or more of the teachings,expressions, embodiments, examples, etc. described herein may becombined with any one or more of the other teachings, expressions,embodiments, examples, etc. that are described herein. Thefollowing-described teachings, expressions, embodiments, examples, etc.should therefore not be viewed in isolation relative to each other.Various suitable ways in which the teachings herein may be combined willbe readily apparent to those of ordinary skill in the art in view of theteachings herein. Such modifications and variations are intended to beincluded within the scope of the claims.

Before explaining the various embodiments of the surgical devices indetail, it should be noted that the various embodiments disclosed hereinare not limited in their application or use to the details ofconstruction and arrangement of parts illustrated in the accompanyingdrawings and description. Rather, the disclosed embodiments may bepositioned or incorporated in other embodiments, variations andmodifications thereof, and may be practiced or carried out in variousways. Accordingly, embodiments of the surgical devices with directionaldampening features disclosed herein are illustrative in nature and arenot meant to limit the scope or application thereof. Furthermore, unlessotherwise indicated, the terms and expressions employed herein have beenchosen for the purpose of describing the embodiments for the convenienceof the reader and are not to limit the scope thereof. In addition, itshould be understood that any one or more of the disclosed embodiments,expressions of embodiments, and/or examples thereof, can be combinedwith any one or more of the other disclosed embodiments, expressions ofembodiments, and/or examples thereof, without limitation.

Also, in the following description, it is to be understood that termssuch as front, back, inside, outside, top, bottom and the like are wordsof convenience and are not to be construed as limiting terms.Terminology used herein is not meant to be limiting insofar as devicesdescribed herein, or portions thereof, may be attached or utilized inother orientations. The various embodiments will be described in moredetail with reference to the drawings.

Turning now to the figures, FIG. 1 illustrates one embodiment of anelectrosurgical instrument 2. The electrosurgical instrument 2 comprisesa two-trigger clamp and cut mechanism. The electrosurgical instrument 2comprises a handle assembly 4, a shaft assembly 12 coupled to a distalend of the handle assembly 4, and an end effector 10 coupled to a distalend of the shaft assembly 12. The handle assembly 4 is configured as apistol grip and comprises left and right handle housing shrouds 6 a, 6b, a closure trigger 8, a pistol-grip handle 14, a firing trigger 16, anenergy button 18, and a rotatable shaft knob 20. An electrical cable 21enters the handle assembly 4 at a proximal end.

The shaft assembly 12 comprises a jaw actuator, a cutting memberactuator, and an outer sheath 23. The jaw actuator is operativelycoupled to the closure trigger 8 of the handle assembly 4. In someembodiments, the outer sheath 23 comprises the jaw actuator. The cuttingmember actuator is operatively coupled to the firing trigger 14 of thehandle assembly 4. The outer sheath 23 comprises one or more contactelectrodes on the distal end configured to interface with the endeffector 10. The one or more contact electrodes are operatively coupledto the energy button 18 and an energy source (not shown).

The energy source may be suitable for therapeutic tissue treatment,tissue cauterization/sealing, as well as sub-therapeutic treatment andmeasurement. The energy button 18 controls the delivery of energy to theelectrode. A detailed explanation of each of these control elements isprovided herein below. As used throughout this disclosure, a buttonrefers to a switch mechanism for controlling some aspect of a machine ora process. The buttons may be made out of a hard material such asusually plastic or metal. The surface may be formed or shaped toaccommodate the human finger or hand, so as to be easily depressed orpushed. Buttons can be most often biased switches, though even manyun-biased buttons (due to their physical nature) require a spring toreturn to their un-pushed state. Terms for the “pushing” of the button,may include press, depress, mash, and punch.

In some embodiments, an end effector 10 is coupled to the distal end ofthe shaft assembly 12. The end effector 10 comprises a first jaw member22 a and a second jaw member 22 b. The first jaw member 22 a ispivotably coupled to the second jaw member 22 b. The first jaw member 22a is pivotally moveable with respect to the second jaw member 22 b tograsp tissue therebetween. In some embodiments, the second jaw member 22b is fixed. In other embodiments, the first jaw member 22 a and thesecond jaw member 22 b are pivotally movable. The end effector 10comprises at least one electrode 92. The electrode 92 is configured todelivery energy. Energy delivered by the electrode 92 may comprise, forexample, radiofrequency (RF) energy, sub-therapeutic RF energy,ultrasonic energy, and/or other suitable forms of energy. In someembodiments, a cutting member (not shown) is receivable within alongitudinal slot defined by the first jaw member 22 a and/or the secondjaw member 22 b. The cutting member is configured to cut tissue graspedbetween the first jaw member 22 a and the second jaw member 22 b. Insome embodiments, the cutting member comprises an electrode fordelivering energy, such as, for example, RF and/or ultrasonic energy.

FIG. 2 illustrates a side perspective view of the electrosurgicalinstrument 2 illustrated in FIG. 1. FIG. 2 illustrates the right handlehousing 6 b. The energy button 18 extends through the handle assembly 4and is accessible on both sides of the handle assembly 4. The closuretrigger 8, the firing trigger 14, and the energy button 18 comprise anergonomic design. In some embodiments, the handle assembly 14 is thinnernear the energy button 18 to allow ease of access to the energy button18 by a clinician. In some embodiments, the energy button 18 is disposedon either the left handle housing 6 a or the right handle housing 6 b.FIG. 3 illustrates a side view of the electrosurgical instrument 2 andthe right handle housing 6 b.

FIG. 4 illustrates one embodiment of the surgical instrument 2 of FIG. 1with the left handle housing 6 a removed. The handle assembly 4comprises a plurality of components for actuating the surgicalinstrument 2, such as, for example, mechanisms for affecting closure ofthe jaws 22 a, 22 b of the end effector 10, deploying a cutting memberwithin the end effector 10, and/or delivering energy to the electrode 92coupled to the end effector 10. A closure trigger 8 is configured totransition the jaws 22 a, 22 b from an open position to a closedposition. The closure trigger 8 is connected to a clamp arm 24. Theclamp arm 24 couples the closure trigger 8 to a yoke 26. When theclosure trigger 8 is actuated towards the pistol grip handle 14, theyoke 26 moves proximally and compresses a closure spring 28. Compressionof the closure spring 28 retracts a jaw actuator, such as, for example,the outer sheath 23, to transition the first jaw member 22 a of the endeffector 10 from an open position to a closed position. In theillustrated embodiment, the closure spring 28 comprises an uncompressedspring. In some embodiments, a partially pre-compressed spring may beused (see FIG. 25).

A firing trigger 16 is configured to deploy a cutting member within theend effector 10. The firing trigger 16 is operatively coupled to acompound gear 42. The compound gear 42 interfaces with a rack 44. Therack 44 is coupled to a firing actuator (not shown). When the firingtrigger 16 is actuated, the compound gear 42 rotates and moves the rack44 distally. The distal movement of the rack 44 causes distal movementof the firing actuator and deployment of the cutting member within theend effector 10. The cutting member is deployed from the proximal end ofthe end effector 10 to the distal end. In one embodiment, the firingtrigger 16 comprises a high pivot to provide a linear feel duringactuation of the firing trigger 16. The linear feel provides increasedcontrol and comfort to a clinician actuating the firing trigger 16.

In some embodiments, the rack 44 comprises a lock mechanism. In theillustrated embodiment, the rack 44 comprises a rack unlock block 40.The rack unlock block 40 interfaces with a lock arm 38 to preventactuation of the cutting member firing switch 16 prior to actuation ofthe closure trigger 8. When the closure trigger 8 is in an openposition, the lock arm 38 interfaces with the rack unlock block 40 tolock the rack 44 and prevent actuation of the firing trigger 16. Whenthe closure trigger 8 is actuated, the yoke 26 raises the lock arm 38away from the rack unlock block 40. When the closure trigger 8 issufficiently actuated, corresponding to the jaws 22 a, 22 b of the endeffector 10 being in a sufficiently closed position to prevent thecutting member from existing a slot in the jaws 22 a, 22 b, the lock arm38 is decoupled from the rack unlock block 40, allowing actuation of thefiring trigger 16.

FIG. 5 illustrates an exploded view of the electrosurgical instrument 2.As shown in FIG. 5, the handle assembly 4 comprises a left handlehousing 6 a and a right handle housing 6 b. The handle assembly 4comprises a closure trigger 8, a firing trigger 16, and an energy button18. A clamp arm 24 is coupled to the jaw closure trigger 8 and a yoke 26by a plurality of pins 52. A mil max connector 53 is located at aproximal end of the handle assembly 4 to couple to an energy source (notshown). Although the illustrated embodiments comprise a surgicalinstrument 2 coupled to an external energy source, those skilled in theart will recognize that the energy source and/or one or more drivecircuits may be located within the handle assembly 4. For example, inone embodiment, a battery and a RF generation circuit may be mounted inthe handle assembly 4 and coupled to the energy button 18. In someembodiments, a jaw position sensor 34 is mounted in the handle assembly4 to indicate when the jaws 22 a, 22 b of the end effector 10 haveclosed beyond a predetermined position. A screw lock spring 36 ismounted to the jaw position sensor 34 to prevent accidental adjustmentof the jaw position sensor 34. A control board 48 is mounted in thehandle assembly 4.

FIG. 6 illustrates a side perspective of the handle assembly 4comprising a jaw closure mechanism in the handle assembly 4. The closuretrigger 8 is illustrated in an initial position corresponding to an openposition of the jaws 22 a, 22 b. In operation, a clinician actuates theclosure trigger 8 to transition the jaws 22 a, 22 b to a closedposition. FIG. 7 illustrates the closure trigger 8 in a partiallyactuated position. As shown in FIG. 7, as the closure trigger 8 isrotated proximally towards the pistol-grip handle 14, the clamp arm 24moves the yoke 26 in a proximal direction to compress the closure spring28. Compression of the closure spring 28 causes the jaws 22 a, 22 b totransition to a closed position and applies a force to tissue graspedbetween the jaws 22 a, 22 b. For example, in some embodiments, theclosure trigger 8 position illustrated in FIG. 7 corresponds to a fullclosure of the jaws 22 a, 22 b. Additional actuation of the closuretrigger 8 increases the force applied by the jaws 22 a, 22 b to a tissuesection grasped therebetween. In other embodiments, full closure of thejaws 22 a, 22 b occurs when the closure trigger 8 is fully actuated. Ahole 19 in the closure trigger 8 allows the closure trigger 8 to beactuated without interfering with the energy button 18. In someembodiments, the hole 19 is covered by the left and right handlehousings 6 a, 6 b.

FIG. 8 illustrates a firing trigger lock mechanism 33. A lock arm 38interfaces with a rack unlock block 40 to prevent actuation of thefiring trigger 16 prior to closure of the jaws 22 a, 22 b. The firingtrigger lock mechanism 33 is unlocked through actuation of the closuretrigger 8. The yoke 26 is coupled to an unlock bar 41. When the yoke 26is moved distally through actuation of the closure trigger 8, the lockbar 41 lifts the lock arm 38 vertically away from the rack unlock block40. When the lock arm 38 has been lifted a sufficient distance, the rack44 is allowed to move distally and the firing trigger 16 is actuatableto deploy the cutting member within the end effector 10. FIGS. 9 and 10illustrate the handle assembly 4 of the surgical instrument 2 with thejaw clamping trigger 8 sufficiently compressed to release the lock arm38 from the rack unlock block 40. As can be seen in FIG. 9, the lock arm38 is lifted a sufficient distance to allow actuation of the firingtrigger 16 prior to full rotation of the closure trigger 8. The firingtrigger 16 is unlocked when the jaws 22 a, 22 b are sufficiently closedsuch that the cutting member cannot skip out of a slot formed in the endeffector 10. For example, in some embodiments, the lock arm 38 isreleased when the closure trigger 8 is compressed about 8 degrees,corresponding to jaw opening of about 2.5 degrees. In other embodiments,the lock arm 38 may be released at a lower or higher degree of rotationof the closure trigger 8.

In some embodiments, a lock spring 64 is coupled to the lock arm 38 toapply a biasing force to the lock arm 38. The biasing force biases thelock arm 38 towards the rack unlock block 40 and maintains the lock arm38 in contact with the rack unlock block 40 until the closure trigger 8has been sufficiently actuated. When the closure trigger 8 is releasedand the yoke 26 returns to a rest position, the lock spring 64 biasesthe lock arm 38 back into a locked configuration with the rack unlockblock 40.

FIG. 10 illustrates the lock arm 38 in an unlocked position. In theunlocked position, a clinician may actuate the firing trigger 16 todrive the rack 44 distally and deploy the cutting member within the endeffector 10. In some embodiments, a jaw position sensor 34 is configuredto indicate when the jaws 22 a, 22 b are sufficiently closed to allowdeployment of the cutting member. In some embodiments, the jaw positionsensor 34 comprises a bypass switch. In other embodiments, other typesof switches may be used, such as, for example, normally open, normallyclosed, and/or other switch types.

FIG. 11 illustrates one embodiment of a jaw position sensor 34. The jawposition sensor 34 comprises an adjustable contact 77. The adjustablecontact 77 is mechanically adjustable to adjust the jaw sense activationpoint of the jaw position sensor 34. The contact 77 is adjusted byrotating a screw 76 coupled to the jaw position sensor 34. Rotation ofthe screw 76 increases or decreases (depending on the direction ofrotation) the necessary height of the lock arm 38, corresponding to aspecific rotation of the closure trigger 8, required to activate the jawposition sensor 34. In some embodiments, such as the embodimentillustrated in FIG. 12, a screw lock spring 36 is coupled to the screw76 to prevent accidental adjustment of the contact 77. In order toadjust the contact 77 in the embodiment illustrated in FIG. 12, thescrew lock spring 36 must be depressed prior to rotation of the screw76. The screw lock spring 36 is released after adjustment of the screw76 to lock the screw 76 in place. In some embodiments, the screw 76comprises a locking thread. Activation of the jaw position sensor 34 maycorrespond to, for example, a distance of about 0.01 inches between thefirst jaw 22 a and the second jaw 22 b.

FIG. 13 illustrates one embodiment of a jaw position sensor 134. The jawposition sensor 134 comprises a switch 170. When the contact 177 of theswitch 170 is depressed by the lock bar 41, an electrical connectionwithin the switch 170 is opened. The break in the electrical connectionof the switch 170 is detected by a two-position connection header 172.The connection header 172 is coupled to, for example, a control board38. A connected receptacle 174 couples the connection header 172 to thehandle assembly 4. FIG. 14 illustrates the jaw sensor 34 mounted in thehandle assembly 4. The handle assembly 4 comprises a plurality of accessholes 79 to allow a clinician to depress the screw lock spring 36 and torotate the screw 76 to adjust the contact 77.

FIG. 15 illustrates one embodiment of the handle assembly 4 with theclosure trigger 8 fully actuated. When the closure trigger 8 is fullyactuated, the yoke 26 compresses the closure spring 28 to a maximumcompression, corresponding to a maximum force applied by the jaws 22 a,22 b. In some embodiments, the jaws 22 a, 22 b may be configured tomaintain a minimal spacing therebetween to prevent damage to componentsof the surgical instrument 2 and/or the tissue section. In otherembodiments, the maximum compression of the closure spring 28corresponds to a fully closed position of the jaws 22 a, 22 b. In someembodiments, full actuation of the closure trigger 8 corresponds to arotation of about 30 degrees. When the closure trigger 8 is fullyrotated against the pistol-grip handle 14, a closure trigger lock 46 isengaged to maintain the closure trigger 8 in a rotated position andtherefore maintain the jaws 22 a, 22 b in a closed position. As shown inFIG. 15, the hole 19 in the closure trigger 8 allows the closure trigger8 to be fully rotated against the pistol-grip handle 14 withoutinterfering with the energy button 18. Once the trigger lock 46 has beenengaged, the clinician may release the closure trigger 8 and the triggerlock 46 maintains the closure trigger 8 in a closed position, asillustrated in FIG. 16.

As shown in FIG. 16, the trigger lock 46 maintains the closure trigger 8in a less than fully retracted position to prevent damage to componentsof the surgical instrument 2 due to over application of force to thejaws 22 a, 22 b. The trigger lock 46 maintains the closure trigger 8 ina sufficiently rotated position to release the lock arm 38 from the rackunlock block 40 and to engage the jaw position sensor 34. For example,in the illustrated embodiment, the trigger lock 46 maintains the closuretrigger 8 at a rotation of about 28 degrees. With the closure trigger 8in a locked position, the clinician may actuate the firing trigger 16 todeploy the cutting member within the end effector 10. In someembodiments, the clinician may actuate the energy button 18 to deliverenergy to a tissue section grasped between the jaws 22 a, 22 b prior toor simultaneously with, deployment of the cutting member.

In various embodiments, the closure trigger 8 provides a mechanicaladvantage in transferring force from the closure trigger 8 to the jaws22 a, 22 b. FIG. 32 is a chart 700 illustrating the mechanical advantage704 of the closure trigger 8 at various trigger angles 702. As shown inFIG. 32, as the angle of the closure trigger 8 increases, for example,by actuating the closure trigger 8 towards the pistol-grip handle 14,the mechanical advantage 704 delivered by the closure spring 28 to thejaws 22 a, 22 b increases. FIGS. 33 and 34 illustrate the force providedby the jaws 22 a, 22 b as the closure trigger 8 is rotated towards thepistol-grip handle 14. FIG. 33 illustrates force 806 delivered by thejaws 22 a, 22 b when no tissue is located within the jaws 22 a, 22 b.FIG. 34 illustrates the force 906 delivered by the jaws 22 a, 22 b whena tissue of about 3 mm thickness is located between the jaws 22 a, 22 b.

As illustrated in FIG. 16, the firing trigger 16 is coupled to acompound gear 42 interfaced with a rack 44. The rack 44 is mechanicallycoupled to a firing actuator (not shown) configured to deploy thecutting member distally within the end effector 10. Rotation of thefiring trigger 16 proximally towards the handle assembly 4 causes therack 44 to advance distally within the handle assembly 4 and drive thecutting member within the end effector 10. FIG. 17 illustrates thehandle assembly 4 with the firing trigger 16 in an actuated position.The compound gear 42 has advanced the rack 44 distally, corresponding tothe cutting member being located at a distal most position within theend effector 10. Advancement of the rack 44 in a distal directioncompresses a spring washer 58. When the clinician releases the firingtrigger 16, the spring washer forces the rack 44 in a proximaldirection, withdrawing the cutting member from the end effector 10. Thefiring trigger 16 comprises a mechanical advantage that adjusts theforce applied by the cutting member with respect to the force applied tothe firing trigger 16. For example, in one embodiment, the firingtrigger 16 comprises a mechanical advantage of 0.6, such that one poundof force applied to the firing trigger 16 corresponds to 0.6 pounds offorce applied by the cutting member to a tissue section grasped withinthe end effector 10. In some embodiments, the firing trigger 16comprises a maximum rotation corresponding to the cutting member beinglocated at a distal-most portion of the end effector 10. For example,the firing trigger 16 may rotate about nineteen degrees to fully deploythe cutting member within the end effector 10. In some embodiments, thehandle assembly 4 comprises a rack-biasing spring 47 configured to biasthe rack in an proximal position. The closure trigger lock 46 isreleased to open the jaws 22 a, 22 b and release tissue grasped therein.

FIG. 18 illustrates one embodiment of a directional return stroke damper32 coupled to the yoke 26 to reduce the force of the return stroke ofthe closure spring 28. The directional return stroke damper 32 dampensthe return stroke of the yoke 26 when the closure trigger 8 is released.In some embodiments, the directional return stroke damper 26 does notaffect than opening stroke of the yoke 26. In some embodiments, thedirectional return stroke damper 26 provides an assist force to the yoke26 during an opening stroke, effectively reducing the force required forcompression of the jaws 22 a, 22 b. FIG. 19 illustrates one embodimentof a directional return stroke damper 32. FIG. 20A illustrates aninterface between the yoke 26 and the directional return stroke damper32 when the closure trigger 8 is fully actuated and the closure spring28 is at a maximum compression. The directional return stroke damper 32comprises a toggle arm 78 and a damping spring 76. The yoke 26 comprisesa damper interface pin 79. The directional return stroke damper 32reduces the force of the closure spring 28 when the closure trigger 8 isreleased from an actuated position. FIGS. 20B and 20C illustrate theinterface between the yoke 26 and the directional return stroke damper32 as the yoke 26 moves distally. For example, when the jaws 22 a, 22 bare released and the closure trigger 8 returns to an unactuatedposition, the interface pin 79 forces the toggle arm 78 down,compressing the damping spring 76 and reducing the load from the closurespring 28 on the closure trigger 8. Once the interface pin 79 pushes thetoggle arm 78 close to over a center pivot, the load on the yoke pin 79goes almost to zero such that the damper effect is eliminated for theremainder of the stroke. FIG. 20D illustrates the toggle arm 78 rotatedpast the center point of the pivot. In some embodiments, during anopening stroke of the yoke 26, the directional return stroke damper 32provides assistance in compressing the spring 28. For example, in theillustrated embodiment, the damping spring 76 exerts a force on the yoke26 during the opening stroke once the yoke 26 has moved the toggle arm78 over the center point.

FIG. 21 illustrates the handle assembly 4 after the closure trigger 8has been released and the jaws 22 a, 22 b have assumed an open position.The closure trigger 8 has returned to an unactuated position withrespect to the pistol-grip handle 14. The closure spring 28 and the rack44 have returned to their respective starting positions. The directionalreturn stroke damper 32 is fully compressed when the closure spring 28is in a rest position.

In some embodiments, the return stroke damper 32 comprises a directionalfluid damper. FIG. 35A illustrates one embodiment of a directional fluiddamper 1132 coupled to a yoke 1126. In the illustrated embodiment, thedirectional damper 1132 comprise an air damper. The directional damper1132 comprises a plunger 1178 located within an air cavity 1135. A ball1177 is located within the air cavity 1135. The plunger 1178 is coupledto a extended portion 1179 of the yoke 1126. When a handle of a surgicalinstrument, such as, for example, the closure trigger 8 of the surgicalinstrument 4, is compressed to close the jaws of an end effector 10, theyoke 1126 moves proximally (to compress the spring 28) and moves theplunger 1178 proximally within the air cavity 1135. Air enters the aircavity 1135 through the distal hole 1175. The ball 1177 moves proximallyand does not interfere with air movement into the cavity during theopening stroke of the yoke 1126. When the closure trigger 8 is released,the yoke 1126 moves distally, the plunger 1178 is driven distally withinthe air cavity 1135, forcing air out of the distal hole 1175. The ball1177 is forced distally and seated in the distal hole 1175 to slow theair flow out of the air cavity 1135. The air resistance generated by theair within the air cavity 1135 generates a force on the plunger 1178,which in turn dampens the return stroke of the yoke 1126 when the jawsof the end effector 10 are released.

FIG. 35A illustrates the directional damper 1132 coupled to a yoke 1126in a fully open position. The yoke 1126 has been driven proximally, forexample, by compressing a closure trigger 8. The plunger 1178 is pulledproximally by the yoke 1126, allowing the air cavity 1135 to fill. FIG.35B illustrates the directional damper 1132 of FIG. 35A during a returnstroke of the yoke 1126. As the yoke 1126 moves distally, the plunger1178 is driven distally within the air cavity 1135. Air is forced aroundthe ball 1177 and out of the opening 1175 located at the distal end ofthe directional air damper 1132. The air within the air cavity 1135generates a proximal force on the plunger 1178, causing the plunger 1178to exert a dampening force on the yoke 1126.

FIG. 36 illustrates one embodiment of a surgical instrument 1204comprising a directional fluid damper 1232 coupled to the yoke 1226. Thedirectional fluid damper 1232 may comprise, for example, a pneumaticdamper, a hydraulic damper, or any other suitable directional fluiddamper. When the closure trigger 8 is rotated towards the pistol-grip14, the yoke 1226 is forced proximally to compress the closure spring28. The closure spring 28 affects closure of an end effector coupled tothe elongate shaft 12. As the yoke 1226 is moved proximally, the plunger1278 moves proximally within the directional damper 1232. Thedirectional damper 1232 does not exert a force on the yoke 1226 duringcompression of the closure spring 28 and does not affect the forcerequired to close the jaws of the end effector. Movement of the yoke1226 in a proximal directional allows a dampening fluid, such as, forexample, a gas or a liquid, to fill a cavity within the directionaldamper 1232. When the closure trigger 8 is released, the yoke 1226 isforced distally by the closure spring 28, causing the plunger 1278 tomove distally within the directional damper 1232. The plunger 1278forces the fluid out of the distal end of the directional damper 1232.The compression of the fluid within the directional damper 1232 exerts adampening force on the return stroke of the yoke 1226. FIG. 37illustrates one embodiment of a directional air damper 1232. Thedirectional air damper 1232 comprises an air cavity 1235. A plunger 1278is longitudinally moveable within the air cavity 1235. A ball 1277 isdisposed within the cavity 1235 to control the flow of air out of thedistal end 1275 of the air cavity 1235. FIG. 38 illustrates oneembodiment of a distal opening 1275 of a directional air damper 1232.

Referring now to FIG. 39, in some embodiments, return stroke dampeningis provided by a compressible yoke pin 1327. The compressible yoke pin1327 is located within a yoke pin track 1329. The compressible yoke pin1327 is coupled to the yoke 1326 to guide the yoke 1326 duringcompression of the closure spring 28. The compressible yoke pin 1327comprises a spring-biased head in contact with the spring. Thespring-biased head is in contact with the yoke pin track 1329. The yokepin track 1329 comprises an incline, such that the yoke pin track 1329is shallowest in a position corresponding to the yoke 1326 in adistal-most position and deepest at a position corresponding to the yoke1326 in a proximal-most position. When the closure trigger 8 is actuatedtowards the pistol-grip handle 14, the yoke pin 1327 slides within theyoke pin track 1329. The spring-biased head expands towards the yoke pintrack 1329. When the closure trigger 8 is release and the yoke 1326moves distally, the yoke pin 1327 moves within the yoke pin track 1329and the spring-biased head is compressed by the incline of the yoke pintrack 1329. Compression of the spring-biased head exerts a dampeningforce on the return stroke of the yoke 1326. In some embodiments, theyoke pin 1327 provides an assistive force during the opening stroke ofthe yoke 1326.

FIG. 40A illustrates one embodiment of a compressible yoke pin 1327. Thecompressible yoke pin 1327 comprises a spring 1325 and a spring-biasedhead 1331. The spring-biased head 1331 is in contact with an inclinedyoke pin track 1329. FIG. 40A illustrates the position of the yoke pin1327 when the yoke 1326 fully compresses the closure spring 28 and thejaws 22 a, 22 b of the end effector 10 are in a closed position. Whenthe closure trigger 8 is released, the yoke 1326 moves distally and thespring-biased head 1331 moves along the inclined yoke pin track 1329 andcompresses the spring 1325. FIG. 40B illustrates the position of thecompressible yoke pin 1327 when the closure trigger 8 has been fullyreleased and the yoke 1326 is in a distal-most position. Thespring-biased head 1331 compressed the spring 1327 as the yoke pin 1327traverses the yoke pin track 1329. The force generated by the spring1325 exerts a dampening force on the return stroke of the yoke 1326 andprovides a return stroke dampening for the closure trigger 8. In someembodiments, movement of the spring-based head 1331 from the positionillustrated in FIG. 40B to the position illustrated in FIG. 40A, forexample, during an opening stroke of the yoke 1326, the spring-biasedhead 1331 provides an assisting force, reducing the force required tofully compress the closure spring 28.

FIG. 41 is a chart illustrating the damper effect on a return loadprovided by a directional return stroke damper 32. The chart 1000illustrates the trigger angle 1002 of the closure trigger 8 plottedagainst the force 1004 applied to the closure trigger 8. As can be seenin FIG. 35, the force applied by the jaws 22 a, 22 b increases to amaximum point at about 18 degrees of rotation of the clamp trigger 8.The dampening force decreases as the clamp trigger 8 is released and thedamper toggle 78 crosses over a center point.

FIG. 22 illustrates one embodiment of a spring washer 158 configured tointerface with a rack spring 59 when the rack 44 is advanced in a distaldirection. The spring washer 158 and the rack spring 59 cause the rack44 to move proximally if the firing trigger 16 is released. FIG. 23illustrates one embodiment of a spring stop 162. The spring stop 162 iscoupled to the proximal end of the closure spring 28.

FIG. 24 illustrates one embodiment of an electrical energy system 80mounted within the handle assembly 4. An energy button 18 is configuredto deliver energy to an electrode 92 coupled to the end effector 10. Theenergy button 18 is coupled to a plurality of power activation wires 82.When the energy button 18 is depressed, a circuit is completed allowingdelivery of energy to the electrode 92. A source path 84 couples anelectrical contact mounted on the distal end of the outer tube 23 of theshaft assembly 12. In some embodiments, the source path comprises theouter tube 23. Alternatively, in some embodiments, the source pathcomprises a solid or stranded conductor housed within the outer tube 23.A return path 85 acts as a return for bipolar RF energy delivered to theelectrode. For monopolar RF energy, the return path may comprise agrounding electrode coupled to a patient. In some embodiments, the poweractivation wires 82 are coupled to a generator. The control board 48 isfurther coupled to the jaw position switch 34 and the generator. Thegenerator may prevent delivery of energy to the electrode 92 unless thejaw position sensor 34 indicates that the jaws 22 a, 22 b are in asufficiently closed position.

FIG. 25 illustrates one embodiment of an electrosurgical instrument 202comprising a pre-compressed closure spring 228. The pre-compressedclosure spring 228 comprises a closure spring having a certainpre-compression before actuation of the closure trigger 8. Thepre-compressed closure spring 228 requires a clinician to apply lessforce to a closure trigger 8 to generate the same amount of force at thejaws 22 a, 22 b when compared to an uncompressed spring. Thepre-compressed spring 228 may further provide a shorter stroke forcompressing the jaws 22 a, 22 b to the same closure or force level as anuncompressed spring. The electrosurgical instrument 204 is otherwisesimilar to the electrosurgical instrument 4 discussed with respect toFIGS. 1-24. For example, closure of an end effector coupled to thesurgical instrument 202 is affected by actuating a closure trigger 8 tomove a yoke 226 proximally to compress the pre-compressed spring 228 andtransition the jaws 22 a, 22 b from an open position to a closedposition. Those skilled in the art will recognize that any of thedirectional return stroke dampers described above may be coupled to theyoke 226 to provide a return stroke dampening force for thepre-compressed spring 228.

FIG. 26 illustrates one embodiment of surgical instrument 302 comprisinga handle assembly 304 having a top-mounted compound gear 342 and rack344. The firing trigger 316 is coupled to the compound gear 342 by aplurality of teeth 343. Actuation of the firing trigger 316 advances therack 344 in a distal direction. The rack 344 is coupled to a firingactuator (not illustrated) which advances a cutting member distallywithin an end effector coupled to the shaft 312. The surgical instrument302 is otherwise similar to the electrosurgical instrument 4 illustratedin FIGS. 1-24. For example, closure of the jaws of an end effectorcoupled to the shaft assembly 312 is affected by actuating a closuretrigger 8 coupled to a yoke 326 to compress a closure spring 328. Thoseskilled in the art will recognize that any of the directional returnstroke dampers described above may be coupled to the yoke 326 to providea return stroke dampening force to the closure spring 328.

FIGS. 27A and 27B illustrate one embodiment of an electrosurgical endeffector 410 comprising a curved shape. The end effector 410 comprises afirst jaw member 422 a and a second jaw member 422 b. The first jawmember 422 a is pivotally coupled by a pivot pin 479 to the second jawmember. The electrosurgical end effector 410 is configured to be coupledto an electrosurgical instrument, such as, for example, theelectrosurgical instrument 2 illustrated in FIGS. 1-24. In someembodiments, the first jaw member 422 a and the second jaw member 422 bare smoothly tapered with the proximal portion of the jaw members 422 a,422 b being the widest portion and the distal end of the jaw members 422a, 422 b being the narrowest portion of the jaw members 422 a, 422 b.The smooth taper comprises a taper in a plane of curvature of the endeffector 410 and parallel to a central axis of the shaft 412. Forexample, in some embodiments, the distal portion of the end effector 410may comprise approximately 25% to 50% of the proximal width of the endeffector 410, such as, for example, 33%. The smooth taper providesbetter dissection while maintaining a wide electrode through most of theend effector 410 for better sealing. The first jaw member 422 a and thesecond jaw member 422 b are curved along a longitudinal axis of the endeffector 410. The curve of the end effector 410 comprises a radius ofcurvature. The radius of curvature may comprise, for example, a radiusof about 1.000″ to about 4.000″.

The taper and curvature of the end effector 410 increase visibility ofthe tip 491. The taper compensates for the loss of force on the tissueon more proximal locations of the end effector 410 providing a moreconstant pressure on the tissue. The smooth transitions along thelongitudinal axis of the end effector 410 and the taper distributedeflection along the length of the end effector 410 and reduce stressconcentration allowing greater loads to be applied by the end effector410. The reduced stresses and deflection permit the end effector 410 tobe lengthened beyond non-curved, non-tapered end effectors. For example,in some embodiments, the end effector 410 comprises a length ofapproximately 23 mm.

In some embodiments, the end effector 410 comprises an offset pivot 486.The offset pivot 486 comprises a pivot point offset from thelongitudinal axis of the shaft 412 and the end effector 410. The offsetpivot enables the use of a linkage-style closure mechanism. The link pin488 and offset pivot 486 provides precise control of the movement of thefirst jaw member 422 a. FIG. 28 illustrates one embodiment of an endeffector 510 comprising an offset pivot 586 coupled to an offsetactuator. The offset actuator comprises a single asymmetric lever arm590 coupled to the first jaw member 522 a. The asymmetric lever arm 590provides additional material around the pivot 586 when compared to atraditional two lever arm end effector.

FIG. 29 illustrates one embodiment of an end effector 610 comprising anoffset pivot 686 and an asymmetric lever arm 690 coupled to a shaft 612.The end effector 610 comprises a first jaw member 622 a and a second jawmember 622 b. The first jaw member 622 a is pivotally moveable withrespect to the second jaw member 622 b. The second jaw member 622 b isfixed. The first and second jaw members 622 a, 622 b comprises a curvedshape having a radius of curvature with respect to a longitudinal axisof a shaft 612. The first jaw member 622 a and the second jaw member 622b comprise a smooth taper from the proximal end to the distal end. Thedistal tip 690 comprises a width less than the width of the proximalsection of the end effector 610. For example, in some embodiments, thedistal tip comprises a width of about 25% to about 50% of the width ofthe proximal section of the end effector 610. The end effector 610 isillustrated in an open position in FIG. 29. In some embodiments,movement of the first jaw member 622 a with respect to the second jawmember 622 b is accomplished by a linked connection between theasymmetric lever arm 690 and an outer sheath 623 of the shaft 612. A lowfriction bushing 698, such as, for example, a lubricious metal orplastic, comprises a sliding interface between the asymmetric lever arm690 and the outer sheath 623. The low friction bushing 698 is disposedbetween an outer diameter of the asymmetric lever arm 690 and an innerdiameter of the shaft 612. FIG. 30 illustrates the end effector 610 ofFIG. 29 in a closed position. As shown in FIG. 30, the end effector 610is transitioned to a closed position by moving the asymmetric lever arm690 proximally. Proximal movement of the asymmetric lever arm 690 may beaffected by, for example, actuating a closure trigger 8 of a handleassembly 4 coupled to the end effector 610 by the shaft 612.

In some embodiments, an electrode 692 is coupled to the second jawmember 622 b. The electrode 692 is adhered to the second jaw member 622b by an adhesive, such as, for example, a silicon or epoxy adhesive. Theelectrode 692 is selectively coated with a ceramic coating that provideselectrical insulation to prevent shorting between the electrode 692 andthe second jaw member 622 b. In some embodiments, the ceramic coatingand adhesive comprise a thermal conductivity of about 0.5 W/(mK) toabout 2.0 W/(mK). The electrode 692 contacts a source electrode on thedistal end of the outer tube 623 when the first jaw member 622 a isrotated into a closed position with respect to the second jaw member 622b. Placement of the contact electrode on the outer shaft 623 ensures agood connection between the electrode 692 and an energy source. In someembodiments, the first jaw member 622 a and/or the second jaw member 622b define a cutting member slot. FIG. 31 illustrates one embodiment ofthe second jaw member 622 b comprising a cutting member slot 696. Theproximal end of the cutting member slot 696 begins in a plane through acentral axis of the shaft 612. The cutting member slot 696 biases to afirst side of the central axis of the shaft 612 then crosses the centralaxis to a location biased to the opposite side of the central axis atthe distal-most portion of the cutting member slot 696. The cuttingmember slot 696 shape maximizes the radius of the cutting member slot696 reducing the bending load on the cutting member 695. The geometry ofthe cutting member slot 696 maintains a nearly equivalent electrode 692width on both sides of the cutting member slot 696. In some embodiments,the curvature of the cutting member slot 696 is substantially equal tothe curvature of the end effector 610, which is substantially equal tothe curvature of the anatomy being transected. In some embodiments, aradius of curvature of the cutting member slot 696 varies from about2.000″ to about 4.000″ over the length of the cutting member slot 696.In some embodiments, the cutting member slot 696 is biased to either thefirst side and/or the second side of the central axis of the shaft 612by a distance of greater than 0.000″ to a maximum of about 0.065″.

While the examples herein are described mainly in the context ofelectrosurgical instruments, it should be understood that the teachingsherein may be readily applied to a variety of other types of medicalinstruments. By way of example only, the teachings herein may be readilyapplied to tissue graspers, tissue retrieval pouch deployinginstruments, surgical staplers, ultrasonic surgical instruments, etc. Itshould also be understood that the teachings herein may be readilyapplied to any of the instruments described in any of the referencescited herein, such that the teachings herein may be readily combinedwith the teachings of any of the references cited herein in numerousways. Other types of instruments into which the teachings herein may beincorporated will be apparent to those of ordinary skill in the art.

It should be appreciated that any patent, publication, or otherdisclosure material, in whole or in part, that is said to beincorporated by reference herein is incorporated herein only to theextent that the incorporated material does not conflict with existingdefinitions, statements, or other disclosure material set forth in thisdisclosure. As such, and to the extent necessary, the disclosure asexplicitly set forth herein supersedes any conflicting materialincorporated herein by reference. Any material, or portion thereof, thatis said to be incorporated by reference herein, but which conflicts withexisting definitions, statements, or other disclosure material set forthherein will only be incorporated to the extent that no conflict arisesbetween that incorporated material and the existing disclosure material.

The disclosed embodiments have application in conventional endoscopicand open surgical instrumentation as well as application inrobotic-assisted surgery.

Embodiments of the devices disclosed herein can be designed to bedisposed of after a single use, or they can be designed to be usedmultiple times. Embodiments may, in either or both cases, bereconditioned for reuse after at least one use. Reconditioning mayinclude any combination of the steps of disassembly of the device,followed by cleaning or replacement of particular pieces, and subsequentreassembly. In particular, embodiments of the device may bedisassembled, and any number of the particular pieces or parts of thedevice may be selectively replaced or removed in any combination. Uponcleaning and/or replacement of particular parts, embodiments of thedevice may be reassembled for subsequent use either at a reconditioningfacility, or by a surgical team immediately prior to a surgicalprocedure. Those skilled in the art will appreciate that reconditioningof a device may utilize a variety of techniques for disassembly,cleaning/replacement, and reassembly. Use of such techniques, and theresulting reconditioned device, are all within the scope of the presentapplication.

By way of example only, embodiments described herein may be processedbefore surgery. First, a new or used instrument may be obtained and ifnecessary cleaned. The instrument may then be sterilized. In onesterilization technique, the instrument is placed in a closed and sealedcontainer, such as a plastic or TYVEK bag. The container and instrumentmay then be placed in a field of radiation that can penetrate thecontainer, such as gamma radiation, x-rays, or high-energy electrons.The radiation may kill bacteria on the instrument and in the container.The sterilized instrument may then be stored in the sterile container.The sealed container may keep the instrument sterile until it is openedin a medical facility. A device may also be sterilized using any othertechnique known in the art, including but not limited to beta or gammaradiation, ethylene oxide, or steam.

It is worthy to note that any reference to “one aspect,” “an aspect,”“one embodiment,” or “an embodiment” means that a particular feature,structure, or characteristic described in connection with the aspect isincluded in at least one aspect. Thus, appearances of the phrases “inone aspect,” “in an aspect,” “in one embodiment,” or “in an embodiment”in various places throughout the specification are not necessarily allreferring to the same aspect.

One skilled in the art will recognize that the herein describedcomponents (e.g., operations), devices, objects, and the discussionaccompanying them are used as examples for the sake of conceptualclarity and that various configuration modifications are contemplated.Consequently, as used herein, the specific exemplars set forth and theaccompanying discussion are intended to be representative of their moregeneral classes. In general, use of any specific exemplar is intended tobe representative of its class, and the non-inclusion of specificcomponents (e.g., operations), devices, and objects should not be takenlimiting.

With respect to the use of substantially any plural and/or singularterms herein, those having skill in the art can translate from theplural to the singular and/or from the singular to the plural as isappropriate to the context and/or application. The varioussingular/plural permutations are not expressly set forth herein for sakeof clarity.

The herein described subject matter sometimes illustrates differentcomponents contained within, or connected with, different othercomponents. It is to be understood that such depicted architectures aremerely examples and that in fact many other architectures may beimplemented which achieve the same functionality. In a conceptual sense,any arrangement of components to achieve the same functionality iseffectively “associated” such that the desired functionality isachieved. Hence, any two components herein combined to achieve aparticular functionality can be seen as “associated with” each othersuch that the desired functionality is achieved, irrespective ofarchitectures or intermedial components. Likewise, any two components soassociated can also be viewed as being “operably connected,” or“operably coupled,” to each other to achieve the desired functionality,and any two components capable of being so associated can also be viewedas being “operably couplable,” to each other to achieve the desiredfunctionality. Specific examples of operably couplable include but arenot limited to physically mateable and/or physically interactingcomponents, and/or wirelessly interactable, and/or wirelesslyinteracting components, and/or logically interacting, and/or logicallyinteractable components.

Some aspects may be described using the expression “coupled” and“connected” along with their derivatives. It should be understood thatthese terms are not intended as synonyms for each other. For example,some aspects may be described using the term “connected” to indicatethat two or more elements are in direct physical or electrical contactwith each other. In another example, some aspects may be described usingthe term “coupled” to indicate that two or more elements are in directphysical or electrical contact. The term “coupled,” however, also maymean that two or more elements are not in direct contact with eachother, but yet still co-operate or interact with each other.

In some instances, one or more components may be referred to herein as“configured to,” “configurable to,” “operable/operative to,”“adapted/adaptable,” “able to,” “conformable/conformed to,” etc. Thoseskilled in the art will recognize that “configured to” can generallyencompass active-state components and/or inactive-state componentsand/or standby-state components, unless context requires otherwise.

While particular aspects of the present subject matter described hereinhave been shown and described, it will be apparent to those skilled inthe art that, based upon the teachings herein, changes and modificationsmay be made without departing from the subject matter described hereinand its broader aspects and, therefore, the appended claims are toencompass within their scope all such changes and modifications as arewithin the true scope of the subject matter described herein. It will beunderstood by those within the art that, in general, terms used herein,and especially in the appended claims (e.g., bodies of the appendedclaims) are generally intended as “open” terms (e.g., the term“including” should be interpreted as “including but not limited to,” theterm “having” should be interpreted as “having at least,” the term“includes” should be interpreted as “includes but is not limited to,”etc.). It will be further understood by those within the art that if aspecific number of an introduced claim recitation is intended, such anintent will be explicitly recited in the claim, and in the absence ofsuch recitation no such intent is present. For example, as an aid tounderstanding, the following appended claims may contain usage of theintroductory phrases “at least one” and “one or more” to introduce claimrecitations. However, the use of such phrases should not be construed toimply that the introduction of a claim recitation by the indefinitearticles “a” or “an” limits any particular claim containing suchintroduced claim recitation to claims containing only one suchrecitation, even when the same claim includes the introductory phrases“one or more” or “at least one” and indefinite articles such as “a” or“an” (e.g., “a” and/or “an” should typically be interpreted to mean “atleast one” or “one or more”); the same holds true for the use ofdefinite articles used to introduce claim recitations.

In addition, even if a specific number of an introduced claim recitationis explicitly recited, those skilled in the art will recognize that suchrecitation should typically be interpreted to mean at least the recitednumber (e.g., the bare recitation of “two recitations,” without othermodifiers, typically means at least two recitations, or two or morerecitations). Furthermore, in those instances where a conventionanalogous to “at least one of A, B, and C, etc.” is used, in generalsuch a construction is intended in the sense one having skill in the artwould understand the convention (e.g., “a system having at least one ofA, B, and C” would include but not be limited to systems that have Aalone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). In those instances where aconvention analogous to “at least one of A, B, or C, etc.” is used, ingeneral such a construction is intended in the sense one having skill inthe art would understand the convention (e.g., “a system having at leastone of A, B, or C” would include but not be limited to systems that haveA alone, B alone, C alone, A and B together, A and C together, B and Ctogether, and/or A, B, and C together, etc.). It will be furtherunderstood by those within the art that typically a disjunctive wordand/or phrase presenting two or more alternative terms, whether in thedescription, claims, or drawings, should be understood to contemplatethe possibilities of including one of the terms, either of the terms, orboth terms unless context dictates otherwise. For example, the phrase “Aor B” will be typically understood to include the possibilities of “A”or “B” or “A and B.”

With respect to the appended claims, those skilled in the art willappreciate that recited operations therein may generally be performed inany order. Also, although various operational flows are presented in asequence(s), it should be understood that the various operations may beperformed in other orders than those which are illustrated, or may beperformed concurrently. Examples of such alternate orderings may includeoverlapping, interleaved, interrupted, reordered, incremental,preparatory, supplemental, simultaneous, reverse, or other variantorderings, unless context dictates otherwise. Furthermore, terms like“responsive to,” “related to,” or other past-tense adjectives aregenerally not intended to exclude such variants, unless context dictatesotherwise.

In summary, numerous benefits have been described which result fromemploying the concepts described herein. The foregoing description ofthe one or more embodiments has been presented for purposes ofillustration and description. It is not intended to be exhaustive orlimiting to the precise form disclosed. Modifications or variations arepossible in light of the above teachings. The one or more embodimentswere chosen and described in order to illustrate principles andpractical application to thereby enable one of ordinary skill in the artto utilize the various embodiments and with various modifications as aresuited to the particular use contemplated. It is intended that theclaims submitted herewith define the overall scope.

Various aspects of the subject matter described herein are set out inthe following numbered clauses:

1. A surgical instrument comprising: a handle assembly comprising: aclosure trigger; a yoke coupled to the closure trigger, the closuretrigger configured to drive the yoke longitudinally in a firstdirection; a closure spring coupled to the yoke, the yoke configured tocompress the closure spring in the first direction; and a directionalreturn stroke damper coupled to the yoke, the directional return strokedamper configured to dampen movement of the yoke in a second direction;a shaft assembly comprising a proximal end and a distal end, wherein theproximal end of the shaft assembly is coupled to the handle; and an endeffector coupled to the distal end of the shaft assembly, the endeffector comprising: a jaw assembly having a proximal end and a distalend, the jaw assembly comprising: a first jaw member; and a second jawmember, wherein the closure spring is operatively coupled to the firstjaw member to pivotally move the first jaw member from an open positionto a closed position relative to the second jaw member when the closurespring is compressed by the yoke.

2. The surgical instrument of clause 1, wherein the directional returnstroke damper comprises: a toggle arm operatively coupled to the yoke;and a damping spring operatively coupled to the toggle arm, wherein theyoke moves in the second direction, the toggle arm compresses thedamping spring, wherein compression of the damping spring generates thedampening force.

3. The surgical instrument of clause 2, wherein the toggle arm pivotsabout a center point, and wherein when the toggle arm is rotated pastthe center point by the yoke, the damping spring stops exerting adampening force on the yoke.

4. The surgical instrument of clause 3, wherein the dampening forcecomprises a maximum force corresponding to a rotation of the closuretrigger of about 18 degrees.

5. The surgical instrument of clause 1, wherein the directional returnstroke damper comprises a directional damper.

6. The surgical instrument of clause 5, wherein the directional airdamper comprises: an air cavity comprising an air flow opening; aplunger located within the air cavity and operatively coupled to theyoke; an air flow ball located within the air cavity.

7. The surgical instrument of clause 5, wherein the directional airdamper comprises a hydraulic damper.

8. The surgical instrument of clause 1, wherein the directional returnstroke damper comprises: a yoke pin track comprising an inclinedsurface; and a compressible yoke pin coupled to the yoke, wherein thecompressible yoke pin is configured to slidingly engage the inclinedsurface.

9. The surgical instrument of clause 8, wherein the compressible yokepin longitudinally is configured to traverse the inclined surface of theyoke pin track when the yoke is moved longitudinally, and wherein theinclined surface is configured to compress the compressible yoke pinwhen the yoke moves in the second direction.

10. The surgical instrument of clause 9, wherein the compressible yokepin comprises: a spring; and a spring-biased head, wherein thespring-biased head is biased towards the inclined surface of the yokepin track by the spring.

11. The surgical instrument of clause 1, wherein the directional returnstroke damper is configured to provide an assisting force tolongitudinal movement of the yoke in the first direction.

12. A jaw closure mechanism for a surgical instrument having an endeffector comprising a first jaw member and a second jaw member, the jawclosure mechanism comprising: a yoke longitudinally moveable in a firstdirection and a second direction, wherein the first and seconddirections are opposite; a closure spring coupled to the yoke, the yokeconfigured to compress the closure spring in the first direction; and adirectional return stroke damper coupled to the yoke, the directionalreturn stroke damper configured to dampen longitudinal movement of theyoke in the second direction.

13. The jaw closure mechanism of clause 12, wherein the directionalreturn stroke damper comprises: a toggle arm operatively coupled to theyoke; and a damping spring operatively coupled to the toggle arm,wherein the toggle arm is configured to compress the damping spring whenthe yoke moves in the second direction, and to generate the dampingforce when the damping spring is compressed.

14. The jaw closure mechanism of clause 13, wherein the toggle arm isconfigured to pivot about a center point, and wherein when the togglearm is rotated past the center point by the yoke, the damping springdoes not exert a dampening force on the yoke.

15. The jaw closure mechanism of clause 14, wherein the dampening forcecomprises a maximum force corresponding to the center point of thetoggle arm.

16. The jaw closure mechanism of clause 12, wherein the directionalreturn stroke damper comprises a directional damper.

17. The jaw closure mechanism of clause 16, wherein the directional airdamper comprises: an air cavity comprising an air flow opening; aplunger located within the air cavity and operatively coupled to theyoke; an air flow ball located within the air cavity.

18. The jaw closure mechanism of clause 12, wherein the directionalreturn stroke damper comprises: a yoke pin track comprising an inclinedsurface; and a compressible yoke pin coupled to the yoke, wherein thecompressible yoke pin is configured to slidingly engage the inclinedsurface.

19. The jaw closure mechanism of clause 18, wherein the compressibleyoke pin is configured to longitudinally traverse the inclined surfaceof the yoke pin track when the yoke is moved longitudinally, and whereinthe inclined surface is configured to compress the compressible yoke pinwhen the yoke moves in the second direction.

20. A surgical instrument comprising: a handle assembly comprising: aclosure trigger defining an energy button hole; a yoke coupled to theclosure trigger, wherein the closure trigger is configured to drive theyoke longitudinally in a first direction; a closure spring coupled tothe yoke, wherein the yoke is configured to compress the closure springin the first direction; and a directional return stroke damper coupledto the yoke, the directional return stroke damper configured to providea dampening force to longitudinal movement of the yoke in a seconddirection; an energy button located within the energy button hole; and afiring trigger; a shaft assembly coupled to the handle assembly, theshaft assembly comprising: an outer tube; a closure actuator operativelycoupled to the closure spring; and a firing actuator operatively coupledto the firing trigger; and an end effector coupled to a distal end ofthe shaft assembly, the end effector comprising: a jaw assembly having aproximal end and a distal end, the jaw assembly comprising: a first jawmember; and a second jaw member, wherein the first and second jawmembers define a longitudinal slot, wherein the closure actuator iscoupled to the first jaw member to pivotally move the first jaw memberfrom an open position to a closed position relative to the second jawmember; and a cutting member deployable within the longitudinal slot,wherein the cutting member is coupled to the firing actuator to advancethe cutting member distally within the longitudinal slot.

What is claimed is:
 1. A surgical instrument comprising: a handleassembly comprising: a closure trigger; a yoke coupled to the closuretrigger, the closure trigger configured to drive the yoke longitudinallyin a first direction; a closure spring coupled to the yoke, the yokeconfigured to compress the closure spring in the first direction; and adirectional return stroke damper coupled to the yoke, the directionalreturn stroke damper configured to dampen movement of the yoke in asecond direction; a shaft assembly comprising a proximal end and adistal end, wherein the proximal end of the shaft assembly is coupled tothe handle; and an end effector coupled to the distal end of the shaftassembly, the end effector comprising: a jaw assembly having a proximalend and a distal end, the jaw assembly comprising: a first jaw member;and a second jaw member, wherein the closure spring is operativelycoupled to the first jaw member to pivotally move the first jaw memberfrom an open position to a closed position relative to the second jawmember when the closure spring is compressed by the yoke.
 2. Thesurgical instrument of claim 1, wherein the directional return strokedamper comprises: a toggle arm operatively coupled to the yoke; and adamping spring operatively coupled to the toggle arm, wherein the yokemoves in the second direction, the toggle arm compresses the dampingspring, wherein compression of the damping spring generates thedampening force.
 3. The surgical instrument of claim 2, wherein thetoggle arm pivots about a center point, and wherein when the toggle armis rotated past the center point by the yoke, the damping spring stopsexerting a dampening force on the yoke.
 4. The surgical instrument ofclaim 3, wherein the dampening force comprises a maximum forcecorresponding to a rotation of the closure trigger of about 18 degrees.5. The surgical instrument of claim 1, wherein the directional returnstroke damper comprises a directional damper.
 6. The surgical instrumentof claim 5, wherein the directional air damper comprises: an air cavitycomprising an air flow opening; a plunger located within the air cavityand operatively coupled to the yoke; an air flow ball located within theair cavity.
 7. The surgical instrument of claim 5, wherein thedirectional air damper comprises a hydraulic damper.
 8. The surgicalinstrument of claim 1, wherein the directional return stroke dampercomprises: a yoke pin track comprising an inclined surface; and acompressible yoke pin coupled to the yoke, wherein the compressible yokepin is configured to slidingly engage the inclined surface.
 9. Thesurgical instrument of claim 8, wherein the compressible yoke pinlongitudinally is configured to traverse the inclined surface of theyoke pin track when the yoke is moved longitudinally, and wherein theinclined surface is configured to compress the compressible yoke pinwhen the yoke moves in the second direction.
 10. The surgical instrumentof claim 9, wherein the compressible yoke pin comprises: a spring; and aspring-biased head, wherein the spring-biased head is biased towards theinclined surface of the yoke pin track by the spring.
 11. The surgicalinstrument of claim 1, wherein the directional return stroke damper isconfigured to provide an assisting force to longitudinal movement of theyoke in the first direction.
 12. A jaw closure mechanism for a surgicalinstrument having an end effector comprising a first jaw member and asecond jaw member, the jaw closure mechanism comprising: a yokelongitudinally moveable in a first direction and a second direction,wherein the first and second directions are opposite; a closure springcoupled to the yoke, the yoke configured to compress the closure springin the first direction; and a directional return stroke damper coupledto the yoke, the directional return stroke damper configured to dampenlongitudinal movement of the yoke in the second direction.
 13. The jawclosure mechanism of claim 12, wherein the directional return strokedamper comprises: a toggle arm operatively coupled to the yoke; and adamping spring operatively coupled to the toggle arm, wherein the togglearm is configured to compress the damping spring when the yoke moves inthe second direction, and to generate the damping force when the dampingspring is compressed.
 14. The jaw closure mechanism of claim 13, whereinthe toggle arm is configured to pivot about a center point, and whereinwhen the toggle arm is rotated past the center point by the yoke, thedamping spring does not exert a dampening force on the yoke.
 15. The jawclosure mechanism of claim 14, wherein the dampening force comprises amaximum force corresponding to the center point of the toggle arm. 16.The jaw closure mechanism of claim 12, wherein the directional returnstroke damper comprises a directional damper.
 17. The jaw closuremechanism of claim 16, wherein the directional air damper comprises: anair cavity comprising an air flow opening; a plunger located within theair cavity and operatively coupled to the yoke; an air flow ball locatedwithin the air cavity.
 18. The jaw closure mechanism of claim 12,wherein the directional return stroke damper comprises: a yoke pin trackcomprising an inclined surface; and a compressible yoke pin coupled tothe yoke, wherein the compressible yoke pin is configured to slidinglyengage the inclined surface.
 19. The jaw closure mechanism of claim 18,wherein the compressible yoke pin is configured to longitudinallytraverse the inclined surface of the yoke pin track when the yoke ismoved longitudinally, and wherein the inclined surface is configured tocompress the compressible yoke pin when the yoke moves in the seconddirection.
 20. A surgical instrument comprising: a handle assemblycomprising: a closure trigger defining an energy button hole; a yokecoupled to the closure trigger, wherein the closure trigger isconfigured to drive the yoke longitudinally in a first direction; aclosure spring coupled to the yoke, wherein the yoke is configured tocompress the closure spring in the first direction; and a directionalreturn stroke damper coupled to the yoke, the directional return strokedamper configured to provide a dampening force to longitudinal movementof the yoke in a second direction; an energy button located within theenergy button hole; and a firing trigger; a shaft assembly coupled tothe handle assembly, the shaft assembly comprising: an outer tube; aclosure actuator operatively coupled to the closure spring; and a firingactuator operatively coupled to the firing trigger; and an end effectorcoupled to a distal end of the shaft assembly, the end effectorcomprising: a jaw assembly having a proximal end and a distal end, thejaw assembly comprising: a first jaw member; and a second jaw member,wherein the first and second jaw members define a longitudinal slot,wherein the closure actuator is coupled to the first jaw member topivotally move the first jaw member from an open position to a closedposition relative to the second jaw member; and a cutting memberdeployable within the longitudinal slot, wherein the cutting member iscoupled to the firing actuator to advance the cutting member distallywithin the longitudinal slot.